A 42-year-old Australian member of a religious cult has been detained in Kenya over the alleged abduction of a young single mother who visited his cult for a trial stay.

Roland Gianstefani was taken into police custody in Nairobi on June 17, but has not been charged despite Kenyan laws preventing police holding suspects without charge for more than 48 hours.

A Foreign Affairs Department spokeswoman said that Mr Gianstefani had been visited by consular officials and had engaged a lawyer.

“The High Commission in Nairobi has made representations to the Kenyan authorities (and) the government is concerned the man has not yet been charged,” the spokeswoman said.

She did not provide details of the abduction allegations.

Mr Gianstefani, who is from New South Wales, is a member of the internet cult Jesus Christians, which is based in Sydney.

An email to AAP from the cult said Mr Gianstefani was detained after a young single mother, known as Betty visited the community in Kenya with her son for a trial stay.

“Near the end of her trial week, her father negotiated with police in Kenya to take Roland prisoner as a way of forcing the mother to leave the community and give herself up to him and the police,” the email said.

The group claimed that Mr Gianstefani is being used as a hostage “by corrupt officials and powerful parents” and that police and relatives had threatened to charge him with kidnapping if Betty does not turn herself in.

“It is not clear whether Roland would be charged with kidnapping Betty or with kidnapping Betty’s seven-year-old son Joshua but the simple facts are that both Betty and Joshua have spoken over the phone to police, assuring them that they have not been abducted.

“Conditions are very rough and Roland is afraid for his safety,” the cult said.

The cult said when members had tried to visit Mr Gianstefani, police had moved him to another police station.

“Police are actively seeking other members of the community, having entered and searched two of our offices when we were not there,” the email said.

Mr Gianstefani and his wife Susan were given suspended six-month jail sentences in 2000 by a court in England after refusing to reveal the whereabouts of an English teenager who left home to join the Jesus Christians.

Bobby Kelly, 16, disappeared in June 2000, saying he wanted to stay with the group and was found a month later living with two men in a tent in a Hampshire forest.

The Gianstefanis were among those who met Bobby at a shopping centre before he disappeared.

The 16-year-old later said he had hoped to remain with the group for the rest of his life.

The Jesus Christians drew attention in Australia last year after revelations they lied to health authorities so that they could donate their kidneys to strangers.

NSW later introduced legislation to legalise live kidney donations by strangers.